1. Field of the Invention
The present invention relates to a power supply apparatus, and more particularly to a current-sharing power supply apparatus that can provide two output voltages with a multiple relation.
2. Description of Prior Art
In electronic engineering, a DC-to-DC converter is an electronic circuit which converts a source of direct current (DC) from one voltage level to another, and the converted DC voltage is stabilized at the preset voltage value. Generally speaking, the DC-to-DC converter is divided into two categories: one is “step-down” DC-to-DC converter (namely, the output voltage is lower than the input voltage), and the other one is “step-up” DC-to-DC converter (namely, the output voltage is higher than the input voltage). The DC-to-DC converter is mainly applied to a distributed power system. Hence, the DC voltage level of the previous stage is fixed, and the DC voltage level of the next stage can be connected to the corresponding DC-to-DC converter according to the required power.
The DC-to-DC converter is normally used to regulate voltage level of an input DC voltage to output a regulated voltage at an output terminal. For practical operation of the power supply, a proper amount of the DC-to-DC converters are essential to generate various voltage levels required to supply different circuits inside the power supply. However, both the costs and the volume of the power supply are increased.